Compass follower



E. F. BRITTEN, JR

COMPASS FOLLOWER Nov. 30, 1948.

Filed June 16, 1943 "7" ;*&

4 Sheets-Sheet 2 ngJn;

Nov. 30, 1948. E. F. BRITTEN, JR 2,455,219

COMPASS FOLLOWER Filed June 16, 1943 I 4 Sheets-Sheet 3 INVENTOR itfenJr.

Nov. 30, 1948. a F. BRITTEN, JR

couPAss FOLLOWER Filed June 16, 1943 a MQ l l I I Il ll Illll lllll 111 llk Patented Nov. 30, 1948 COMPASS FOLLOWER Edwin F. Britten, Jrl, Short Hills, N. J., assignor to Monroe Calculating Machine Company, Orange, N. J a corporation of Delaware Application June 16, 1943, Serial No. 491,257

3 Claims. (Cl. 346-4) The invention has relation to follower, devices e for magnetic compasses, these devices being of the type wherein a hunting action is established by successive reversals of the follower drive.

The invention consists in the novel construction and combination of parts as set forth in the appended claims.

In the accompanying drawings illustrating the invention:

Fig. 1 is a diagrammatic plan view of a compass and of certain of the associated follower elements.

Fig: 2 is a side elevation of the planetary differential gearing, the reversing means thereof and the means for operating said reversin means.

Fig. 3 is a view similar to Fig. 2, with parts omitted,taken from the opposite side, and showing the motor and associated parts.

Fig. 4 is a detail side view, taken from the same side as Fig. 2, of the planetary differential gearing, with parts removed.

Fig. 5 is a plan view of the motor drive, the

diil'erential planetary gearing and its reversing means interposed in said drive and the means for operating said reversing means, associated with integrating means of an odograph, parts being broken away.

Fig. 6 is. a side elevation of means. 4

Fig. 'l is a plan view of the plotting mechanism of an odograph designed for operation through said integrating means.

Fig. 815 a detail sectional view, taken longitudinally of the drive shaft, with parts broken away.

The magnetic compass and the electrical porsaid integrating from this mirror will strike one of two mirrors 28, 24, angularly disposed upon the wall of the closure 20, one at either side of slot 2 I, and will be reflected therefrom to one or the other of two.

photo-electrictubes 25, 26.

Tubes 26 and 26 have electrical connectioneach with one of a pair of thyratron tubes 21, 28, these tubes being biased through a rheost-at 29 as shown diagrammatically in Fig. l. Either one of these thyratron tubes, being excited by an electric current passing through the related photo-electric tube, serves to establish a circuit of comparatively high voltage through one or the other of a pair of solenoids 30-, 3|, which in turn control means for rotating plate I8 in one or in the other direction. I

Movement transmission means in the form of planetary differential gearing to be described and having reversing means is interposed in. the drive between electric motor 33, (Figs. 3 and 5) and a pinion (Fig. l) meshing with gear teeth formed in the periphery of said plate I8. Electrically energized means controlled by said followerfdevice is provided for operating said re- Y thev tubes 25, 28, in known manner, so that the tion of the follower devices are herein shown in a preferred form, disclosed in an application for Patent Serial Number 473,355 filed by Edwin F.

Britten, Jr.,'on' January 23, 1943 now- Patent 2,325,365, July 27, 1943;

The follower mechanism of the compass is con trolled by-photo-electric devices comprising a source of light I9 (Fig. 1) mounted within a,

closure 20 having'a vertical slot 2| in its innerwall, light from source I! passin through slot/2|,

and striking a mirror It fixed upon the frame which carries the compass needle I3. The 0105- ure 20,,together with the photo-electric tubes to mounted within the compass casing, and upon;

versi ameans to thereby successively reverse the direction of rotationof said transmission and of said drive to. eflect oscillatory hunting action as will be described. Thus the'plate l8 and the partscarried thereby will be rotated'first in one andvthen in the other direction, as controlled by source of light will be carried around the compass bowl in following relative movement of the needle.

The movement transmission means 10,- the latter having driving connection with driven shaft I29 including the aforesaid planetary dlflerential gearing interposed in the drive.

This planetary differential gearing has two oppositely rotatingcontrollable-members one of which is an inter'nally toothed gear wheel I32 provided with annular series of outer peripheral teeth. I34; and supported by spokes I32 from a; hub freelyrotatable. on the hub Joining members I21 I and I2! to be-described. Theother controllable member comprises a spur gearlfl and a wheel I33.'- made 'fast;thereto by pins I3I",--saidwheel be described, are carried on a rotary ,platei8- the compass is mounted, the parts carried upon the plate will move relatively to the compass] needle and mirror It. so that the light reflected I33 having an annular series of peripheral teeth I24 of'the same diameter as. that of'said'flrst named. series Ifl.v A-circularcarrier'plate I21 1 ounted to rotate freely upo'ndrive shaft 10 has connected to its hub a gear I22 which engages 'gear I28! flxed'to drive the shaft I29. Planet gears I26 have the 'shafts'thereofloosely mounted in bearings of said plate I21, the two larger of said planet gears meshing with sun gear I25 fast upon the drive: shaft I and with said internally toothed gear I32 of the one controllable member of said transmission and the two smaller of said planet gears meshing with spur gear N3 of the other controllable member. The planetary different'ial gearing is provided with a reversing lever I35, fulcrumed upon shaft I36 and having opposite arms adapted respectively for engagel0 ment with the peripheral teeth E34 of the gear wheel I32 of the one controllable member of said transmission, unalternatively with the peripheral teeth I34 of the wheel I33 of the other con= trollable member. third arm provided at the free end thereof with opposite spaced plates I38.

The electrically energized means controlled by the followers mechanism for the purpose stated comprises two solenoids 39, iii, a lever iii fillcrumed upon shaft llll having opposite arms pivotally connected with the cores 80, iii of said solenoids, one arm of said lever Mi having a finger extension I33 loosely engaged between said plates I38.

. Operation In operation, one of the solenoids-til, 8i,

being energized and one arm of the reversing lever 8 being engaged, say with the peripheral teeth I34 of gear 882, this controllablemember of the planetary differential gearing will be held stationary, the result being that the sun gear l25 fast upon the drive shaft it will revolve the planet gears lit around said sun gear in one di- 3.;

rection, thereby, through the gearing its, lit driving the shaft I|29 in one direction. The other of said solenoids being energized and the other arm of said reversing lever H35 being engaged with the peripheral teeth lat of wheel i133, the ll) other controllable member or the planetary differential gearing will be held stationary, the re= suit being that the sun gear M5 will revolve the planet gears I26 therearound in the opposite di= rection, thereby, through gearing its, E128 driving the shaft I29 in the opposite'direction. 4

The driven shaft 629 is connected with pinion 95 by means not shown.

The gear ratios of the differential are such that the speed of the driven shaft 325) is the same in forward or in reverse drive, but, since the oppositely rotating elements i3 3, i553 are not driven at the same speed, they are provided with difierent numbers of teeth, so that a given number of teeth of either element will pass a fixed point in a given time; Thus, there will be no lag of one element, in picking up the drlverelatively to the action of the other element. 7

The integrator components (such as north or south and east or west) of the progressive movement of a vehicle may be integrated to effect the movement of a stylus to record upon a chart thedirection and extent of such movement, that is to say, to record the path of the vehicle.

.In the present application an odograph is asnown, whereby a map or chart; is plotted to rep:

This reversing lever has a 15 4 resent'the course of a conveyance. The chart table is shown in Fig. '7, wherein a holder 86 for a pen, pencil or stylus 9! is mounted on cross rods 88, 89, in known manner, movement of holder 88 and stylus 81 being determined by the travel of nuts 89' much right angularly disposed threaded rods 9|, the latter being rotated by gears '92 from said integrating means as-wlll be explained. The cross rods 98 have at the ends thereof pinions 89 traveling upon racks 90.

The progressive movement of the conveyance is measured through the driving motion of a propeller shaft; automatic log; speedometer or other appropriate source, from which motion is transmitted through a shaft 93 (Figs. 5 and 6).

Rotation of shaft 93 is transmitted through gearing 94 to toothed cylinders 95, 98, these cylinders being driven in opposite directions at a speed proportional to the rate of advance of the conveyance.

The teeth of cylinders 95, 96 are of graded lengths, a line traced through the ends of the teeth, in the development of the cylindrical surface of the cylinder, giving a sine curve.

The pinions 91 are mounted upon splined shafts 98, located upon opposite sides of and havin their longitudinal axes parallel to the cylinders 95, 98, these pinions meshing with the teeth 91 of said cylinders and being moved longitudinally thereof by means of fingers 99 of bars 99' located upon opposite sides or said shafts 98, said bars being mounted upon reciprocatory plates I00, the latter being carried by links Illl, pivoted at one end thereof at mi and at their other ends pivoted upon shafts Hill. The plates itliand consequently the pinions Eli are reciprocated by means of two rollers W2 of crank arms I92 located upon opposite sides of a shaft W3 having hearings in the stationary framing, said crank arms being disposed at right angles to each other, and said shaft I83 being driven by gears ltd from said shaft I29.

Shafts 98, 98 are provided with worms W5, I95, meshing with worm wheels its, i116 fast respectively upon a shaft lil'i and a sleeve Hi8. this shaft and sleeve having respective gearing connection (not shown) with the gears 92 associated with the chart table. Thus, in regulating the travel of the pencil ill, the sine curve of the graded teeth of cylinders 95, t8, together with the relation of the rollers let, i632, provide for movements of the two gears 92 in accordance with the sine and cosine components, respectively, or the travel of the conveyance. y

A switchv I42 (Figs. 5 and 6) is interposed in the circuit of the electric motor 38, this switch being r not running, the gear 94 which is carried by shaft 93 is designedto be moved axially out of mesh with the next adjacent gear of the driving train. This is effected by mounting gear 94 on a splined sleeve, longitudinally movable by means of a roller I49 mounted upona pivoted member I50 having link connection lSI with rocker I48. In order to provide for flexible movement of the adjacent devices 5-148, I59, I5I, the link I5I is provided with pin and slot connection with rocker I48, and a spring I52 serves to hold the parts normally in contacting position. However,

in case the gears do not immediately mesh when it is at 'mpted to reengage them, spring ill will yield an rocker I will be allowed to come into full adjusted position. The rocker is held in either of its two adjusted positions, against suitable stops, by means of a toggle spring I535 A spring I may connect arm I" and link I in order to lock these parts as set to inoperative position, with the pivotal connection thereof beyond dead center.

In order to provide a slip clutch effect, the gear 84 may be mounted loosely upon the slidable sleeve and pressed by spring I into contact with friction disks I58, one of which is fast to said sleeve.

The herein described invention is of particular advantage in controlling the action of integrating means of th type employing oppositely rotating cylinders having longitudinally extending teeth of graded lengths and axially reciprocatory pinions engaging said teeth. This is because it is desired to integrate .the different directional.

components of the progressive movement of a vehicle byinfinitely fine gradations rather than by graded steps governed by the difference between the length of the teeth, to thereby record upon the chart the-true direction and extent of the'progressive movement of the vehicle, that is to say to more accurately record the path of the vehicle. For this Purpose, the reciprocating travel of the pinions 91 should be at a uniform are averaged. between the number of teeth encountered in the plane of the longer tooth and the number encountered when this longer tooth does not act upon the pinion. c

This effect could not be obtained if the known type of reversing mechanism were used, consisting of a pole reversing switch, whereby the armature of the motor is caused to rotate first in one and then in the otherdirection. This known-mecha nism gives a motion which approaches the harmonic, and the resulting travel of the integrator pinions 91 would be plotted .as a succession of sine Thus-the pinion 91, during its reciprocation over the pathstated will, over ashort period of time, receive movements which assume remain out of engagement with the shorter tooth for half the interval of time required for its travel back and forth between the end of one tooth and that next adjacent thereto comprising photo opposite direction, said transmission having re-' ciprocatory driving connection with said pinions,

and electrically energized means controlled by said follower mechanism for operating said reversing means.

2. The combination with an odograph having a stylus and means for integrating the different directional components of the progressive movement of a vehicle to eil-ectmovement of said stylus and record the course of the vehicle, said integrating means comprising oppositely rotating cylinders having driven connection with the propeller shaft of the vehicle, said cylinders having circumferential series of longitudinal teeth of such graded lengths that an imaginary line traced through the ends of the teeth in the development of the cylindrical surface will give a sine curve, and axially reciprocating pinions meshing with said teeth; of means for accomplishing the axial reciprocation of said pinions at a uniform speed so that a pinion which at one end of its throw is located half way between the ends of two adjacent of said teeth will remain out of engagement with the shortertooth for h It the interval of time follower mechanism, said rotary drivingconnection comprising movement transmissionmeans" having reversing means, said transmission having reciprocatory driving connection-with saidpin ions, saidreciprocatory driving connection comprising a shaft having radial arms located at right angles to each other and provided with end rollers and reciprocatory plates engaged by said rollers, said plates having means of engagement with said pinions to reciprocate the latter, and electrically energized means controlled by said follower curves. Ontheother hand, the reversing 'mechanism of the present invention -gives a. uniform motion 'to the pinions 81, which may be plotte as a saw tooth curve.

Iclaim: I l. The combination with an odograph. having a stylus'and means for integr ting the diflerent directional-components of the progressive movement of a vehicle to effectgmovement of said I stylus andrecord the course of the vehicle,

said integrating means comprising oppositely rotating cylinders having driven connection with the propeller shaft of the vehicle, said cylinders having circumferential series .of

" longitudinal teeth of such graded moguls that an imaginary line traced through the ends-of said teeth in the development of the cylindrical sur-.

mechanism for operating said reversing means. 3. The combination-with an odograph having a stylus and means for integrating the different directional components. of the progressive 'move- I ment of a vehicle to effect movement ofsaid stylus and record the path of the vehicle, said integrat ing means comprising oppositely rotating cylinders having driven connection with the propeller shaft of the vehicle, said cylinders having circumferential series of longitudinal teeth of such' graded lengths that an imaginary line traced reciprocation of said pinions ,at a uniform speed so that a pinion whichatone'endfofits throw isv located half way between the' ends of two adjacent of said teethwill remain out of engagementwith the shorter tooth-for half th'ednterva'l of time required for its travel back and forthbetween the end of one tooth; and that 'nextfadlacent thereto comprising photo-electrically] controlled Y r motor-driven oscillatory hunting-type follower mechanism for magnetic compasses the motor of which has rotary driving connection with said 101- lower mechanism, said rotary driving connection comprising movement transmission means having reversing means, said transmission having reciprccatory driving connection with said pinions, and electrically energized means controlled by said follower mechanism for operating said reversing means comprising two solenoids, said transmission comprising'ciifierential gearing having two oppositely rotating toothed controllable mem-bers and said reversing means comprising a, lever opposite arms of which are adapted respectively to engage the teeth of one or alternatively the other of said controllable members and a second lever opposite arms of which have pivotal connection with the cores of said solenoids and one arm of which has operating connection with the first named lever.

. EDWIN BRI'ITEN, JR.

REFERENQES CJTLTEE The following references are off record in the file of this patent:

Number Numoer UNITED STATES PATENTS Name Date Hall Mai. 31, 1914 Sperry Jan. 15, 1924 Pearson Mar. 15, 1932 Hugersliot! Aug. 23, 1932 Hill Oct. 25, 1932 Hodzman Nov. 8, 1938 Nichols Oct. 3, 1939 Muller -July 9, 1940 Britten July 27. 1934 FOREIGN PATENTS Country Date Great Britain Sept. 26, 1932 France June 6, 1924 France Aug. 13, 1926 France June 16, 1931 

